NASA: Water On Mercury

NASA announced Thursday that its Messenger probe has discovered new evidence of water ice on Mercury.

In the announcement, Sean Solomon, principal investigator for the Mercury Messenger program, said the probe had uncovered new evidence that deposits in permanently shadowed regions of Mercury's poles is water ice. The ice is found predominantly in impact craters, according to data obtained by Messenger.

According to a NASA press release, the tilt of Mercury’s rotational axis is almost zero -- less than one degree -- so there are pockets at the planet’s poles that never see sunlight. Scientists suggested decades ago that there might be water ice at Mercury’s poles, but the new findings provide"compelling support" for that claim.

Messenger used neutron spectroscopy to measure average hydrogen concentrations, an indicator of water ice.

Very interesting. Except for the high delta-V requirement, I think Mercury is a better destination than Mars, since it receives about 20 times the sunlight intensity that Mars does. With ice at the poles a viable processing facility would be relatively easy since a horizontal solar collector extended above the lip of a crater would receive the full intensity of Mercury sunlight, and due to the lack of axial tilt the collector would only have to pivot around a vertical axis.